Gaseous conduction lamp



June 5, 1928 1,672,285

F. SCHAEFER GASEOUS CONDUCTION LAMP Filed Aug. 27, 1927 INVENTOR BY Q "6A TTORNE 1 arm or branch 8.

Patented June 1 928.

' UNITED STATES 1,672,285 PATENT OFFICE- FRANK SCHAEFEB, OF KAL AMAZOO,MICHIGAN, ASSIGNOBOF ONE-HALF TO AMERI- CAN SIGNS CORPORATION, OF KALAMAZOO, MICHIGAN.

' Gaseous connuc'r on nun.-

The main object of this invention is to provide a gaseous conductionlamp or 1 luminescent tube which maybe embodied in the form of a letteror other indicia for 5 signs or ornamental purposes.

A further object is to provide a luminescent tube lamp structure whichis economical to produce and one in which the finished product isattractive as there are no return bends in the inain'tube such as arecommonly employed in forming letters having arms, or so-called blockletters, as distinguished from script. p

'Objects pertaining to details and economies of my invention will appearfrom the description to follow. 'The invention is defined in the claims.

A structure embodying the features of my invention is clearlyillustrated in the accompanying drawing forming a part of thisspecification, in which: an

Fig.1-'s an illustration of a. sign Iconsisting of the word AMSCOembodying my invention. Fig. 2 is a detail view partially in section ofthe letter A .embodying the features of my invention. v

Fig. 3 is a perspective view of the letter K embodying my invention.

Referring to the drawing, the structure illustrated in =Fig. 1 is a lampof the gase-.

- ous conduction type which consists of a tube .designated generally bythenumeral 1 and having electrodes 2 at it's ends. This tube is adaptedto contain a gaseous medium which glows or becomes incandescent whensubject to electric currents on the use of certain so-called rare gasessuch as neon,

helium andcertain other gaseous mediums In Fig. 1 the letter Cl,designated by the numeral 5, also has an arm or branch 6 closed atitsouter end, and the letter O, designated by the numeral 7, has asimilar In Fig. 3 the letter K, designated by the numeral 9, had the armor branch por- "a'nce, the inner tubes being invisible when The lettersor other indicia are formedof' tions 1t) and 11. This letter.K is formedas a complete unit having electrodes 12 at its ends] 1 Referring to Fig.2, it will be noted that the arm or branch 2 is of the same diameter asthe. main tubular body of the letter. Disposed centrally within thisbranch is an inner tube 13 opening at itsouter end ad acent the outerend of the arm 4. 'Theinner end of this inner tube is autogenouslyjoined to the walls of the main or. outer tube at 14, thereby providinga return passage through the branch or arm. The same is true of the armsor'branches 6 and 8 thereby providin a continuous passage including thebranc es or arms for the gaseous medium.

The outer tube is coated at '15 to render the tube at these pointsopaque so that the letters will appear as separate letters.

By this means I am able to form substantially any desired letter orluminous figure for use in signs or ornamental work with branches orarms where desired without foldingthe main tube upon itself as is theuniversal practice so far as I am aware to produce such results oreffect. I

.Lamps or structures embodying my improvements are very attractive inappear the lam is an operation and, further, are notvisi leexcept onquite close inspect-ion when the lamp is not in operation.

I have not attempted to illustrateor describe various adaptations of myimprovements as it is believed that the disclosure made will enablethose skilled in the art to adapt or embody my improvements as may be 1esired. Q

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is: v j

1. A gaseous conduction lampstructure comprising a plurality of lettersformed of an outer tube,'certain of said letters having 100 arm-likeparts closed at. their outer ends,

and inner tubesof a'diameter smaller than that of said arm-like partsdisposedcentrally within such arm-like parts and openingl thereto attheir outer ends,,-the .inner 1 en s of said inner tubes being expandedvand joined to the walls of the outer tube roviding a continuous passage,"including the. said arm-like parts, fora gaseousmedium.

2. A gaseous conduction lampgc omprising -1l an outer tube having abranch or arm closed at its outer end, and an inner tube of smallerdiameter than said arm disposed therein with its outer end openingadjacent the outer end of said arm, its inner end being joined to theouter tube at one side of the arm providing a continuous passage for agaseous medium adapted to glow when subjected to an electric discharge,and electrodes disposed at the ends of said outer tube.

3. A gaseous conduction lamp comprising an outer tube having arm-likeparts closed at their outer ends, and inner tubes of less diameter thansuch arm-like parts disposed centrally therein and with their outer endsopening adjacent the outer ends of such armlike parts, and their innerends autogenously joined to the Walls of the outer tube at points inadvance of the arm-like parts providing return passages in such arm-likeparts open to the main passage.

4. A gaseous conduction lamp comprising a main or outer tube having abranch closed at .its outer end, and an inner tube of less diameter thansaid. branch disposed central ly'therein and with its outer end openingadjacent the end of such branch, the inner end of said inner tube beingautogenously joined to the Wall of the outer tube in advance of thebranch, closing the main passage in the tube andp'roviding a continuouspassage, including said branch, for the gaseous medium.

5. A gaseous conduction lamp comprising an outer tube having an arm-likepart closed at its outer end, and an inner tube of less diameter thansuch arm-like part disposed therein and with its outer end openingadjacent the outer end of such arm-like part and its inner end joined tothe-wall of the outer tube at one side of the arm-like part providing areturn passage in such arm-like part open to the main passage. j

6. A gaseous conduction lamp comprising a main or'outer tube'having abranch closed

